GB 30253-2024 'Energy Efficiency Limit Values ​​and Energy Efficiency Levels of Permanent Magnet Synchronous Motors' is a mandatory national standard released!

In a squirrel-cage three-phase asynchronous motor, the quality of the cast aluminum rotor directly determines the rotor loss of the motor. Based on some manufacturing and design experience, for cast copper rotors, the additional loss of the rotor is about 0.5% of the rated power. For cast aluminum rotors, The additional loss of the motor accounts for about 1% to 3% of the rated power. Therefore, under the current development trend of efficiency and energy saving, it is necessary to control the additional loss of the rotor and take some technological measures to reduce the additional loss of the motor. The additional loss of the motor rotor is There are many types. For cast aluminum and cast copper rotors, since there is no insulation between the conductor bars and the rotor slots, the leakage current between the conductor bars through the rotor teeth generates part of the rotor loss. This part of the additional loss accounts for about 1% to 2% of the rated power. %. Due to the existence of additional losses, the motor efficiency decreases and the temperature increases. In order to reduce the additional loss of the cast aluminum rotor

In 2021, Germany's Mahle released a new type of magnetless motor that does not require rare earth materials.Moreover, the efficiency of this motor can reach more than 95% under almost any working condition, which was only achieved by Formula E racing cars before.

There are two types of motors currently used in electric vehicles - permanent magnet synchronous motors and non-magnetic induction AC asynchronous motors.Permanent magnet synchronous motor technology is mature and efficient, so it is used in most electric vehicles with single motor designs. For example, the Tesla Model 3 long-range version has a rear single motor.But the permanent magnet motor has a big disadvantage - it requires the use of precious rare earth materials.There are also shortcomings such as the slightly higher price of permanent magnet synchronous motors and the easy demagnetization at high temperatures.